Bathing units, such as spas, whirlpools, hot tubs, bathtubs and swimming pools, often include a water holding receptacle, water pumps, a heating module to heat the water, a filter system, an air blower, a lighting system, and a control system for activating and managing the various parameters of the bathing unit components.
In use, the water pumps typically circulate the water between the water holding receptacle and the heating module in order to heat the water. The heating module is typically controlled by a temperature regulation device which selectively activates/deactivates the heating module in order to set and maintain the water in the bathing unit within a temperature range associated to a desired temperature. A risk associated with heating the water in the bathing unit is that the temperature regulation device, or actuators for activating and deactivating the heating module might malfunction, which could cause the water temperature in the bathing u nit to become unsafe. Accordingly, various safety regulation agencies, such as UL, CSA and TUV, have made certain requirements for bathing units in order to avoid injuries due to unsafe water temperatures. As such, most bathing units are equipped with safety devices that are independent of the temperature regulation device, such that if the water temperature becomes too hot, the safety devices are able to prevent the heating module from continuing to heat the water.
Typically, the temperature regulation device is operative for controlling the activation/deactivation of the heating module by controlling an actuator, such as a relay or switch, which controls the voltage applied to the heating module. A deficiency with such systems is that the burden of causing the heating module to be activated and deactivated is placed on one actuator. Standard relay actuators do not provide a lifetime exceeding approximately 100,000 cycles at full load. As such, after 5–10 years, the relay actuator will fail and will need to be replaced. This is often both costly and frustrating for the bathing unit owner, since the complete bathing unit temperature control system usually needs to be returned for replacement.
In addition, the temperature regulation device is operative for controlling the activation/deactivation of a water pump which circulates water between the water receptacle and the heating module. Generally, the temperature regulation device controls the activation/deactivation of the water pump by controlling an actuator, such as a relay or switch, which controls the voltage applied to the water pump. An additional deficiency with temperature control systems as described above, is that the water pump and/or the actuator, also has a finite life expectance, after which time the water pump will need to be replaced.
Against the background described above, it appears that there is a need in the industry to provide a temperature control system suitable for a bathing unit that alleviates at least in part the problems associated with the existing bathing units.